Merck & Co., Inc. Bank of America Merrill Lynch HCC May 13, 2015

Roy D. Baynes Senior Vice President Global Clinical Development Merck Research Laboratories

Forward-Looking Statement

This presentation includes “forward-looking statements” within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of Merck’s management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; Merck’s ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of Merck’s patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in Merck’s 2014 Annual Report on Form 10-K and the company’s other filings with the Securities and Exchange Commission (SEC) available at the SEC’s Internet site (www.sec.gov).

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Merck is Positioned for Long-Term Growth through Innovation

Premier Research-Driven Biopharmaceutical Company

New Focused Model Suite of Opportunities

Improving Operating Model

Accelerating BD Strategy

Four Key Growth Platforms

Multiple New Product Launches

Programs in Areas with Large Unmet Needs

Advancing Innovative Pipeline

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Merck is Advancing its Innovative Pipeline

2015 2016 2017 2018 2019+ 2014

KEYTRUDA – NSCLC (KN-010)

Grazoprevir / Elbasvir (Hepatitis C)

KEYTRUDA – Bladder Cancer (KN-045)

Anacetrapib (Atherosclerosis)

Actoxumab / Bezlotoxumab (C. Diff. Infection)

Ertugliflozin* (SGLT-2 Inhibitor)

Letermovir (HCMV prophylaxis)

BACE Inhibitor (Alzheimer’s Disease)

Surotomycin (C. Diff. Infection)

Earliest study primary completion date per clinicaltrials.gov Latest study primary completion date per clinicaltrials.gov

KEYTRUDA – Head & Neck Cancer (KN-040)

Omarigliptin* (once weekly DPP-4)

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Doravirine (HIV)

* Light green arrow reflects CV outcomes studies for Omarigliptin and Ertugliflozin.

There is an unmet medical need for an interferon-free, ribavirin-free, short duration HCV therapy that is highly effective across patient populations, including patients with cirrhosis.

Hepatitis C: Fast-growing market with high unmet need

• In U.S., 3.2 million people with chronic HCV – 50% diagnosed – ~170,000 – 200,000

successfully treated – >450,000 may get insurance

between 2014 and 2020

• Without changes to historical diagnosis and treatment paradigm, annual medical costs expected to rise to $85 billion in 5 years

Source. Hepatitis C in the United States, Holmberg, NEJM 2013; Decision Resources (2013), Health care reform and Hepatitis C: a convergence of risk and opportunity - Milliman , 2013; CDC Draft Recommendations – May 18, 2002

The number of patients with chronic HCV infection and cirrhosis will peak in the next 7-10 years

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1950

1960

1970

1980

1990

2000

2010

2020

2030

Num

ber o

f Cas

es

Year

Cirrhosis M 50+

M 31-50

M 0-30

F 50+

F 31-50

F 0-30

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• High rates of efficacy* demonstrated against key genotypes in a broad range of patients, including patients with cirrhosis, HIV co-infection, and other co-morbidities

• High barrier to resistance and activity against common resistance-associated variants of HCV

• Single tablet given once-daily, no significant food effect • Breakthrough designation from FDA for selected populations

HCV NS3/4A inhibitor (100 mg once-daily, oral)

All-oral, once-daily, fixed-dose tablet

HCV NS5A inhibitor (50 mg, once-daily, oral)

Grazoprevir/Elbasvir regimen for the treatment of HCV infection

Grazoprevir (MK-5172)

Elbasvir (MK-8742)

*Defined as Sustained Virologic Response 12 weeks post-treatment, or SVR12 6

• C-CREST: Phase 2 program evaluates two different 3-drug regimens • Designed to target broad range of genotypes • Starts with 8 week regimens, and based on the results, will proceed to

investigate shorter durations

Looking to the future: The Merck triplet regimens

HCV NS5B Nucleoside inhibitor

HCV NS3/4A inhibitor HCV NS5A inhibitor

Grazoprevir (MK-5172)

Elbasvir (MK-8742) or

MK-8402 MK-3682

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Merck is Committed to the Treatment of Hepatitis C

• Hepatitis C is a priority area for Merck

• There is significant unmet need across a large and diverse group of patients infected with Hepatitis C

• At EASL, Merck Grazoprevir/Elbasvir regimen demonstrated high rates of virologic efficacy in Phase 3 C-EDGE and Phase 2/3 C-SURFER studies

– Anticipated filing in H1 2015

• C-CREST Phase 2 studies are ongoing for an 8-week Merck triplet regimen

– Results anticipated in 2015

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Merck is Committed to Immuno-Oncology

• Oncology is a priority area of focus for Merck

• Our strategy: – Building a foundation with monotherapy – Expanding experience in combination therapy

• At present we have more than 90 clinical trials – across more than 30 tumor types and more than 14,000 patients

• New pivotal data for advanced melanoma and non-small-cell lung cancer (NSCLC) presented at AACR and published in the New England Journal of Medicine

• Data now in 8 tumor types, including new data in pleural mesothelioma

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0 2 4 6 8 10 12 14 16 18

30

40

50

60

70

80

90

100

Time, months

O v e

r a l l

S u r v

i v a l

, %

No. at risk 279 266 248 233 219 212 177 67 277 266 251 238 215 202 158 71 278 242 212 188 169 157 117 51

19 18 17

0 0 0

Analysis cut-off date: March 3, 2015.

Pembrolizumab 10 mg/kg every 2 weeks Pembrolizumab 10 mg/kg every 3 weeks Ipilimumab

Keynote-006: KEYTRUDA Demonstrates Overall Survival Advantage vs. Ipilimumab in Advanced Melanoma

Median (95% CI), mo

Rate at 12 mo

HR (95% CI)

P

NR (NR-NR) 74.1% 0.63 (0.47-0.83)

0.00052

NR (NR-NR) 68.4% 0.69 (0.52-0.90)

0.00358

NR (12.7-NR) 58.2% — —

10

0 50 100 150 200 250 300 3500

10

20

30

40

50

60

Time, days

Patie

nts

With

a G

rade

3-5

AE,

%

No. at risk278 230 188 139 98 45 22 1277 233 179 140 97 47 17 0256 182 6 1 1 1 1 0

aAdverse events are presented regardless of causality. Analysis cut-off date: September 3, 2014.

Keynote-006: Time to First Grade 3-5 Adverse Eventa In Advanced Melanoma

Pembrolizumab 10 mg/kg every 2 weeks Pembrolizumab 10 mg/kg every 3 weeks Ipilimumab

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ORR by PD-L1 Proportion Score: CTA-Evaluable Validation Set Patients With Measurable Disease

45.2 43.9 50.0 16.5 15.6 19.2 10.7 9.1 16.7 0

102030405060708090

100

OR

R (9

5% C

I), %

PS ≥50% PS 1-49% PS <1%

an = 73, 103, and 28, respectively. bn = 57, 77, and 22, respectively. cn = 16, 26, and 6, respectively. dn = 78, 61, and 17, respectively. ORR was assessed per RECIST v1.1 by central review in the biomarker-evaluable population (ie, patients with measurable disease per RECIST v1.1 by central review at baseline whose slides were cut within 6 months of staining and for which a proportion score could be assigned). Analysis cut-off date: August 29, 2014.

Totala Previously Treatedb Treatment Naivec

When measurable disease is NOT required, the ORR (95% CI) in the PS ≥50% subgroups are: 42.3%, 41.0%, and 47.1% in the total, previously treated, and treatment-naive populationsd

Keynote-001: Assessing NSCLC Clinical Outcomes by PD-L1 Biomarker

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OS was assessed in all patients whose samples were stained within 6 months of cutting. Analysis cut-off date: August 29, 2014.

n at risk 119 92 56 22 5 4 3 0

161 119 58 15 6 4 0 0

76 55 33 8 0 0 0 0

100

90

80

70

60

50

40

30

20

10

0 0 4 8 12 16 20 24 28

Ove

rall

Surv

ival

, %

Time, months

PS 1-49%

PS <1%

PS ≥50%

PS Median (95% CI), mo

≥50% NR (13.7-NR) 1-49% 8.8 (6.8-12.4) <1% 8.8 (5.5-12.0)

Keynote-001: Overall Survival by PD-L1 Expression, All CTA-Evaluable Patientsa

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REGISTRATION

Broad Merck Immuno-Oncology Pipeline

PHASE 1 AND PHASE 2

1L Melanoma (KN006)

2L Melanoma (KN002)

2/3 L NSCLC (KN010)

2L Bladder (KN045)

Adjuvant Melanoma (KN054)

1L NSCLC (KN024)

Melanoma & NSCLC (KN001)

Head & Neck, Bladder, TNBC, & Gastric (KN012) Hematologic malignancies (KN013) MSI-high Colerectal and non-colon (KN016)

Melanoma brain metastasis (KN027)

Ongoing

Planned

MK-4166 (Anti-GITR): Solid tumors

2L Gastric (KN061)

2L Head & Neck (KN055)

3L Gastric (KN059)

Hodgkin’s Lymphoma (KN087) Triple Negative Breast (KN086)

Pediatric melanoma, solid tumors, lymphoma (KN051)

2L Head & Neck (KN040)

1L NSCLC (KN042)

1L Bladder (KN052)

20-tumor signal-finding study (KN028)

STUDIES

40+ Additional Investigator-Initiated Monotherapy and Combination Studies

RCC (KN031)

NSCLC (Japan) (KN025)

Melanoma (Japan) (KN041)

MK-8628 (BET inhibitor): Solid tumors, hematologic malignancies

Combination

1L Head & Neck (KN048)

RCC with pazopanib (KN018, GSK)

RCC with axitinib (PFE)

HER2+ breast with trastuzumab

Solid tumors with 41BB (KN036, PFE)

Multiple Myeloma with len. & dex. (KN-023)

Melanoma / RCC with IPI/Sylatron (KN029)

Melanoma with T-VEC (AMGN)

NSCLC with abraxane (KN026)

NSCLC with chemo, Ipi, kinase inh’s. (KN021)

Melanoma BRAF & MEK Inh. (KN022, GSK)

NSCLC with Xalkori (PFE)

NSCLC with IDO1 (KN037, INCY)

Prostate with Lm-LLO (KN046, ADXS)

NSCLC with chemo (KN011)

NSCLC with necitumumab (LLY)

Solid Tumors with ramucirumab (LLY) Solid Tumors with lenvatinib (Eisai)

TNBC with eribulin (Eisai)

Melanoma with entinostat (Syndax)

NSCLC with entinostat (Syndax)

Solid Tumors with birinipant (TetraLogic)

Melanoma with PLX3397 (CSF-1R, Plexxikon)

Solid Tumors with PLX3397 (CSF-1R, Plexxikon)

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ASCO: Multiple Presentations in Advanced Malignancies

Selected Titles Type/Session Date

Antitumor activity and safety of pembrolizumab in patients (pts) with advanced squamous cell carcinoma of the head and neck (SCCHN): Preliminary results from KEYNOTE-012 expansion cohort

Oral Presentation; Head and Neck Cancer

Monday, June 1 3:39PM–3:51PM

Long-term efficacy of pembrolizumab (pembro; MK-3475) in a pooled analysis of 655 patients (pts) with advanced melanoma (MEL) enrolled in KEYNOTE-001

Oral Presentation; Melanoma/Skin Cancers

Saturday, May 30 2:39PM–2:51PM

Atypical patterns of response in patients (pts) with metastatic melanoma treated with pembrolizumab (MK-3475) in KEYNOTE-001

Oral Presentation; Developmental Therapeutics and Translational Research

Monday, June 1 1:15PM–1:27PM

Association of response to programmed death receptor 1 (PD-1) blockade with pembrolizumab (MK-3475) with an interferon-inflammatory immune gene signature

Oral Presentation; Developmental Therapeutics and Translational Research

Monday, June 1 1:27PM–1:39PM

Phase I study of pembrolizumab (pembro; MK-3475) plus ipilimumab (IPI) as second-line therapy for advanced non-small cell lung cancer (NSCLC): KEYNOTE-021 cohort D

Clinical Science Symposium; Lung Cancer

Sunday, May 31 4:54PM–5:06PM

Pembrolizumab (MK-3475) in patients (pts) with extensive-stage small cell lung cancer (SCLC): Preliminary safety and efficacy results from KEYNOTE-028

Oral Presentation; Lung Cancer

Saturday, May 30 3:48PM–4:00PM

PD-1 blockade in tumors with mismatch repair deficiency Clinical Science Symposium; Special Sessions

Saturday, May 30 8:05AM-8:17AM

Relationship between PD-L1 expression and clinical outcomes in patients with advanced gastric cancer treated with the anti-PD-1 monoclonal antibody pembrolizumab (MK-3475) in KEYNOTE-012

Oral Presentation; Gastrointestinal (Noncolorectal) Cancer

Sunday, May 31 8:12AM-8:24AM

Pembrolizumab (MK-3475) for patients (pts) with advanced esophageal carcinoma: Preliminary results from KEYNOTE-028

Clinical Science Symposium; Gastrointestinal (Noncolorectal) Cancer

Sunday, May 31 4:54PM-5:06PM

Pembrolizumab (MK-3475) for advanced urothelial cancer: Updated results and biomarker analysis from KEYNOTE-012

Oral Presentation; Genitourinary Cancer

Monday, June 1 10:09AM-10:21AM

Antitumor activity and safety of pembrolizumab in patients (pts) with PD-L1 positive advanced ovarian cancer: Interim results from a phase Ib study

Clinical Science Symposium; Gynecologic Cancer

Monday, June 1 3:12PM-3:24PM

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Frank Clyburn President, Global Oncology

Potential Launches in Multiple Tumor Types

OTHERS

BLADDER

MELANOMA

HEAD & NECK

NON-SMALL- CELL LUNG

GASTRIC

CLASSICAL HODGKINS LYMPHOMA

TRIPLE NEGATIVE BREAST CANCER

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ADVANCED PLEURAL

MESOTHELIOMA

• Initial market entry in metastatic melanoma • Second indication in non-small-cell lung cancer • Possible application in up to 30 different types of tumors

Rapid Penetration of Ipilimumab-Refractory Melanoma

• $83mm in Q1 2015 sales

• Vast majority of ipilimumab-refractory melanoma patients being treated with KEYTRUDA

• Strong access in labeled indication

• Broad acceptance of KEYTRUDA in NCCN melanoma treatment guidelines

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Lung Cancer: Largest Global Incidence and Worst Mortality

Source: GLOBOCAN 2012: Estimated cancer incidence, mortality and prevalence worldwide, in 2012.

0 500,000 1,000,000 1,500,000 2,000,000

Lung Breast

Colorectum Prostate Stomach

LiverHead & Neck

CervixEsophagus

Bladder Non-Hodgkin's lymphoma

Leukemia Pancreas

KidneyEndometrium

Thyroid Brain & CNS

Ovary Melanoma

Gallbladder Multiple myeloma

Hodgkin's lymphoma

IncidenceMortality

Number of Cancer Cases Per Year

Incidence of Lung Cancer ~8x Melanoma

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U.S. Fully Prepared for Lung Indication

• Significant overlap with melanoma HCP’s

− Sales force expansion completed 1Q15

• Substantial education planned • Heavy focus on community-

based KOLs • Preparing for companion

diagnostic

Lung Treaters ~9200 HCPs

Melanoma Treaters ~6,200 HCPs

Overlap ~4,700 HCPs

Unique Lung HCPs ~4,500

Unique Mel HCPs

~1,500

Maximizing opportunity in NSCLC with reach into the

community oncology setting

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Companion Diagnostic: Identifying Patients Who May Benefit Most from Treatment with KEYTRUDA

PS <1% PS 1-49% PS ≥50%

No PD-L1 Expression

Low PD-L1 Expression

High PD-L1 Expression

Correlation with Improved Outcomes

• Diagnostic testing for treatment decisions has become a standard and widespread practice in NSCLC

• PD-L1 diagnostic may help identify patients who may benefit most from treatment with KEYTRUDA

• Enables physicians to have personalized conversations with patients

• Empowers physicians to prioritize treatment options

• Payers are interested in potential health economics

Value of PD-L1 Diagnostic to Customers

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Preparing for Launch in Key ex-U.S. Markets

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KOL engagement

• KOLs identified and plans developed

• Regulatory and reimbursement support secured

• Expanding clinical and medical teams

Customer-Facing Organizations

• Building Commercial,

Medical, and Sales teams

• Field expansion in progress

Scientific Awareness

• Majority of oncologists engaged for Melanoma

• Strong awareness pre-launch

o High in Melanoma

o Building in NSCLC

Merck is preparing to launch KEYTRUDA in Europe, Canada, Japan, and other Global Markets

2015: Merck Looking Forward to...

• Ongoing U.S. melanoma launch and other global markets

• Anticipated approval in NSCLC in U.S. and melanoma in EU

• Anticipated full approval from Keynote-002 submission in U.S. for ipilimumab-refractory melanoma

• Filing of KN-006 data for ipilimumab-naïve melanoma

• Data updates, including new tumors, at ASCO and other medical meetings

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